Push/pull clip feed configuration for selectively delivering or withdrawing a clip to allow output of one clip alone or two clips concurrently and associated devices, methods, systems and computer program products

ABSTRACT

Methods and apparatus for supplying a clip to a clip window associated with a closure attachment mechanism having a closure punch path for attaching a single clip or two clips to a target tubular work piece in a closure zone include: (a) forcing a plurality of clips to travel in a first predetermined clip travel path having a forward direction toward a first punch path in a closure zone at a first point in time; (b) selectively retracting the plurality of clips so that the clips travel in a reverse direction along the first predetermined clip travel path; and then (c) forcing the plurality of clips to again travel in the forward direction along the first predetermined clip travel path at a second point in time.

RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional ApplicationSerial No. 60/470,327, filed May 14, 2003, the contents of which arehereby incorporated by reference as if recited in full herein.

FIELD OF THE INVENTION

[0002] The present invention relates to apparatus that can selectivelyapply closure clips to casing materials that enclose products therein.

BACKGROUND OF THE INVENTION

[0003] Conventionally, in the production of consumable goods such asfood or meat products, the food is fed (typically pumped) or stuffedinto a casing in a manner that allows the casing to fill with a desiredamount of the product. The casing can be produced so that it is sealedat selected locations to form a series of single discrete products or aseries of linked “chubs.”

[0004] One manner of producing a packaged product employs a piece goodspackaging machine that can form a single or discrete packaged product orchub. In operation, a first clip is applied to the beginning portion ofthe casing, the casing is filled with product, and then a second clip isapplied to the end portion of the casing. The process is repeated toprovide a series of discrete piece good packaged products.

[0005] Another way of producing a packaged product employs a shirredcasing machine that can be configured to produce a series of singleproducts or a series of chained products. In operation, a clip isapplied to the beginning portion of a casing and food is pumped into thecasing and the filled casing is moved downstream from the filling point.The filling can be interrupted momentarily while excess product isvoided (pushed away from a clip zone on the package) and two clips canbe applied concurrently to the casing at proximate but spaced apartlateral locations in the clip zone. A knife is used to separate thecasing between the two concurrently applied clips to produce a sealedsingle package. This region between the two clips is sometimes describedas the “tail” or end of the package. The first or forwardmost of the twoclips forms the end of the forward (first) sealed product and the secondor rearwardmost of the two clips forms the beginning of the nextupstream package, which is now ready for filling which is restarted.

[0006] For certain consumable products, such as meat and/or sausage,there is often a desire to produce a series of closed packages that arelinked or chained together. Thus, similar to the shirred single pieceproduction method, two clips can be applied concurrently to a voidedcasing region, which action is repeated a number of times before cuttingany of the links to generate a series or chain of linked “chubs.” Thus,in operation, a desired number of chubs can be serially produced to formthe desired length of product or number of chubs. This process can bedescribed as a “chubbing operation.” After the desired length of productand/or number of chubs is generated, the casing is voided and the twoclips are concurrently applied to the casing as described above. Theknife is then directed to cut the chain at the tail and start a newchain of linked product. The linked or chained products are typicallyvertically suspended together for further processing. See, e.g., U.S.Pat. Nos. 3,543,378, 5,167,567, 5,067,313, and 5,181,302, the contentsof which are hereby incorporated by reference as if recited in fullherein.

[0007] During a conventional chubbing operation, an unused (non-stuffed)length of casing or packaging material extends outwardly from theenclosed product between the first and second concurrently appliedclips. The amount of unused length of casing can vary depending on thepackaging machine, the type of package and/or product.

[0008] In certain applications, it is desirable to reduce the amount ofunused lengths of casing to be able to do one or more of: reduce productcosts (material cost savings), increase the amount of yield in thecooking facility, and suspend additional amounts of product or numbersof chubs on or in conventional racks for increased space utilization.

[0009] U.S. Pat. No. 5,495,701 proposes a clip attachment mechanism forfastening a single clip or two clips simultaneously. The mechanism hastwo punches, one of which is driven directly by a pneumatic cylinder andthe other of which is connected to the first punch using a pin and keyassembly. The pin and key assembly allows the punches to be coupled ordecoupled to the pneumatic cylinder drive to apply one single clip ortwo clips simultaneously. U.S. Pat. No. 5,586,424 proposes an apparatusfor movement of U-shaped clips along a rail. The apparatus includes aclip feed for advancing clips on a guide rail and the arm isreciprocally driven by a piston and cylinder arrangement. The contentsof each of these patents are hereby incorporated by reference as ifrecited in full herein.

[0010] Despite the foregoing there remains a need for devices andmethods that can provide reduced amounts of unused casing materialbetween adjacent sealed products and or additional links in a chainhaving a desired length for increased processing efficiency.

SUMMARY OF EMBODIMENTS OF THE INVENTION

[0011] Embodiments of the present invention provide devices, systems,methods and computer program products for selectively advancing andretracting clips along a clip feed path to automatically feed orwithdraw a clip from a clip attachment mechanism to apply one closureclip alone or two closure clips concurrently to an encased product.

[0012] Certain embodiments are directed to methods for supplying a clipto a clip window associated with a closure attachment mechanism having aclosure punch path for attaching a single clip or two clips to a targettubular work piece in a closure zone. The method includes: (a) forcing aplurality of clips to travel in a first predetermined clip travel pathhaving a forward direction toward a first punch path in a closure zoneat a first point in time; (b) selectively retracting the plurality ofclips so that the clips travel in a reverse direction along the firstpredetermined clip travel path; and then (c) forcing the plurality ofclips to again travel in the forward direction along the firstpredetermined clip travel path at a second point in time.

[0013] The forcing steps can be carried out by pushing the clips forwardalong a clip feed path and the retracting step can be carried out bypulling the clips rearward along the clip feed path.

[0014] Other embodiments are directed to methods for supplying a clip toa clip window associated with a closure attachment mechanism having aclosure delivery path for allowing attachment of a single clip or twoclips to a target tubular work piece in a closure zone. The methodsinclude: (a) pushing a plurality of clips to travel in a firstpredetermined clip travel path having a forward direction toward a firstclosure delivery path in a closure zone at a first point in time; (b)selectively pulling the plurality of clips so that the clips travel in areverse direction along the first predetermined clip travel path; andthen (c) pushing the plurality of clips to again travel in the forwarddirection along the first predetermined clip travel path at a secondpoint in time.

[0015] Other embodiments are directed to apparatus for supplying a clipto a clip window associated with a closure attachment mechanism having aclosure delivery path for attaching a single clip or two clips to atarget tubular work piece in a closure zone. The apparatus includes: (a)means for forcing a plurality of clips to travel in a firstpredetermined clip travel path having a forward direction toward a firstclosure delivery path in a closure zone at a first point in time; (b)means for selectively retracting the plurality of clips so that theclips travel in a reverse direction along the first predetermined cliptravel path; and then (c) means for forcing the plurality of clips toagain travel in the forward direction along the first predetermined cliptravel path at a second point in time.

[0016] The apparatus may include means for holding the plurality ofclips above a first clip window associated with the first closuredelivery path in the closure zone for a desired interval, the intervalassociated with the number of target tubular workpieces that passthrough the closure zone without receiving a clip from the first closuredelivery path.

[0017] Still other embodiments are directed to systems for attachingclosure clips to elongate or tubular products held in casing materials.The systems include: (a) a curvilinear clip rail having opposing top andbottom end portions and defining a generally downwardly extending clipfeed direction; (b) a clip entry window in communication with the bottomend portion of the clip rail and a clip closure delivery path incommunication with an attachment mechanism that is adapted to wrap aclip about a target tubular work piece; (c) a clip pusher configured toselectively engage with clips held on the clip rail to force the clipsin the feed direction; and (d) a clip retraction assembly configured toselectively engage with clips held on the clip rail to force the clipsaway from the clip window and away from the clip feed direction.

[0018] In certain embodiments, the systems may also include: (e) a firstactuation cylinder in communication with the clip pusher; (f) a secondactuation cylinder in communication with the clip retraction member; and(g) a control module configured to direct the actuation of the first andsecond cylinders to selectively feed (and hence not continuously feed) aclip through the clip window.

[0019] Still other embodiments are directed to computer program productsfor operating a shirred casing voiding/clipping apparatus having twoproximate clip attachment mechanisms with first and second clip travelpaths to selectively deliver one clip or two clips concurrently to achain of linked chub product. The computer program products include acomputer readable storage medium having computer readable program codeembodied in the medium. The computer-readable program code includes: (a)computer readable program code that controllably actuates a firstactuation cylinder to push clips in a first clip feed direction; and (b)computer readable program code that controllably actuates a secondactuation cylinder to pull clips away from the clip feed direction.

[0020] In certain embodiments, the computer readable program code canallow a user to select a desired number of links of chubs and/or adesired chain length of linked chubs and computer program code thatdirects the first and second actuation cylinders to apply theappropriate number of single and dual clips at the appropriate links inthe chain.

[0021] These and other objects and/or aspects of the present inventionare explained in detail in the specification set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022]FIG. 1 is a side elevation view of a prior art apparatus used toapply clips via a clip punch attachment mechanism.

[0023]FIG. 2A is a block diagram of operations that can be carried outaccording to embodiments of the present invention.

[0024]FIG. 2B is a schematic diagram of a linked product having singularand dual closure clips according to embodiments of the presentinvention.

[0025]FIG. 3 is a schematic illustration of components of embodiments ofthe present invention.

[0026]FIG. 4 is a flow chart of operations that can be carried outaccording to embodiments of the present invention.

[0027]FIG. 5 is a perspective view of a clip retraction assemblyaccording to embodiments of the present invention.

[0028]FIG. 6 is a right side view of the retraction assembly of FIG. 5in an exemplary rest position according to embodiments of the presentinvention.

[0029]FIG. 7 is a front view of the retraction assembly shown in FIG. 6in the exemplary rest position.

[0030]FIG. 8A is a back view of the retraction assembly shown in FIG. 5with the clip pusher assembly in an extended state and the clip pusherengaged with clips to advance same along a feed direction according toembodiments of the present invention.

[0031]FIG. 8B is a back view of the retraction assembly shown in FIG. 8Awith the clip pusher assembly in a retracted state and the clip pusherdisengaged from the clips.

[0032]FIG. 9A is a front view of the clip retraction assembly shown inFIG. 5 illustrated with the clip retraction cylinder in a retractedstate and the retraction jaw engaged with the clips according toembodiments of the present invention.

[0033]FIG. 9B is a back view of the clip retraction assembly shown inFIG. 5 with the clip retraction cylinder in the retracted state and theretraction jaw engaged with clips while the pusher is disengaged.

[0034]FIG. 9C is a bottom view of the clip retraction assembly shown inFIG. 9B with the retraction jaw disengaged.

[0035]FIG. 10 is a block diagram of a data processing system accordingto embodiments of the present invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0036] The present invention will now be described more fullyhereinafter with reference to the accompanying figures, in whichembodiments of the invention are shown. This invention may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein. Like numbers refer to like elementsthroughout. In the figures, certain layers, components or features maybe exaggerated for clarity, and broken lines illustrate optionalfeatures or operations unless specified otherwise. In addition, thesequence of operations (or steps) is not limited to the order presentedin the claims unless specifically indicated otherwise. Where used, theterms “attached”, “connected”, “contacting”, “coupling” and the like,can mean either directly or indirectly, unless stated otherwise. Theterm “concurrently” means that the operations are carried outsubstantially simultaneously.

[0037] In the description of the present invention that follows, certainterms are employed to refer to the positional relationship of certainstructures relative to other structures. As used herein, the term“front” or “forward” and derivatives thereof refer to the general orprimary direction that the clips travel toward a target product forclosure and/or the direction that the target filled or stuffed productin casing material travel; this term is intended to be synonymous withthe term “downstream,” which is often used in manufacturing or materialflow environments to indicate that certain material traveling or beingacted upon is farther along in that process than other material.Conversely, the terms “rearward” and “upstream” and derivatives thereofrefer to the directions opposite, respectively, the forward anddownstream directions.

[0038] The present invention is particularly suitable for applyingclosure clips to seal flexible products held in casings. The product maybe a linked chain of elongated extruded product held in a casing. Thecasing can be any suitable casing (edible or inedible, natural orsynthetic) such as, but not limited to, collagen, cellulose, plastic,elastomeric or polymeric casing. The elongated or tubular product can bean elongated meat product. Exemplary meat products include, but are notlimited to, strands of meat (that may comprise pepperoni, poultry,and/or beef or other desired meat), and processed meat productsincluding whole or partial meat mixtures, including sausages, hotdogs,and the like. Other embodiments of the present invention may be directedto seal other types of food (such as cheese) or other product in casingmaterials. Examples of other products include powders such as granularmaterials including grain, sugar, sand, sand and the like or otherflowable materials including wet (similar to that held conventionally incans) pet food or other powder, granular, solid, semi-solid orgelatinous materials. The product may be a packaged in any suitableindustry including food, aquaculture, agriculture, environment,chemical, explosives, or other application.

[0039] The elongated product can be produced in a linked chain oftubular or chub product. The length and diameter of each link or chub aswell as the overall length of the chain can vary depending on the typeof product being produced. Examples of typical strand or chain lengthsare between about 1-6 feet.

[0040] Generally stated, clips are applied to the casing material towrap around and close or seal the product therein. The seal formed bythe clip against the casing may be sufficiently strong so as to be ableto hold a vacuum of about 16 mm Hg for about 24-48 hours. Examples ofsuitable clips include metallic generally “U” -shaped clips availablefrom Tipper Tie, Inc., in Apex, N.C. Other clips, clip materials andclip configurations may also be used.

[0041] Referring to FIG. 1, one example of a prior art clip attachmentapparatus with a clip advancement mechanism is illustrated. Typically,the clip attachment apparatus includes a housing 10 that defines aclosure delivery path or channel 12 for receipt of a U-shaped metal clip14. The clip 14 is advanced in the closure path or channel 12 by meansof a punch 16 so that the clip 14 will engage a die 18 positioned in amanner permitting the clip 14 to be formed about gathered material 20that encases the product in the material 20 at closure zone 20 z in theproduct travel path. Although not illustrated, pressurized air or othermeans of pressing or moving the clip to close about the tubular packagemay also be used.

[0042] Each clip 14 is typically fed from a clip guide rail 22 through aclip window 24 into the closure path or channel 12 so that a respectiveone of the clips can be aligned in the path 12. As shown, the guide rail22 has a curvilinear configuration with a vertical run 23 which iscurved at its lower end so that it gradually merges into a horizontalrun 25 to direct clips 14 mounted thereon into the window 24. As shownin FIG. 1, the clips 14 are typically arranged in a stack 15 withadjacent clips 14 abutting each other so that the legs 26 of each clip14 fit around the guide rail 22 with a crown 28 of each clip 14 fittingover the guide rail 22. The multiple clips 14 may be connected to oneanother by means of a thin elastomeric film, tape or adhesive 30(typically along the crown 28) so that the clips 14 together may slidedown the guide rail 22 and around the bend therein between the verticaland horizontal runs 23, 25 of the guide rail. Typically, clips 14 areprovided in a coil or on a reel 34 for feeding onto the guide rail 22.The reel 34 is schematically depicted in FIG. 1 for feeding of the clips14 onto the guide rail 22. Although illustrated herein as a generallyvertical and downwardly directed clip feed, other feed orientations(upward, lateral, angular or the like) may also be used.

[0043] Turning now to FIG. 2A, operations that can be used to carry outembodiments of the invention are shown. A plurality of clips are forced(by gravity and/or active propulsion) to travel in a first predeterminedclip travel path having a forward feed direction toward a first closuredelivery path (such as a punch path) in a closure zone at a first pointin time (block 100). The plurality of clips are selectively retracted sothat the clips travel in reverse along the first predetermined cliptravel path (so that no clip is fed into the clip window) (block 105).The clips are then forced to travel in the forward feed direction alongthe first predetermined travel path at a second point in time (block110).

[0044] The forcing operations can be carried out by urging a push pawlagainst one or more of the clips to force the clips to travel in agenerally downward and/or forward direction (block 101). The retractingoperation can be carried out by using a retraction jaw that can closeabout the exterior of at least one (typically a plurality) of clips todraw the clips away from the clip window or punch channel (block 106).The forward and reverse motion of the clips (which may be carried out bypushing and pulling the clips) can be automatically performed using acontrol module that actuates cylinders associated with a respective oneof the push pawl and retraction jaw to direct the timing thereof (block109). When the clips are moved forward, a clip can be fed through thechannel 12 (FIG. 1) to close about an underlying product; when the clipsare retracted, although a punch may still operate in the channel 12, itpunches a blank or air as no clip is in the channel. This method allowsa single clip to be applied to a plurality of the tails of the chubswhile the dual clips are applied only to selected chubs (such as thechubs at the beginning and/or end of the chain).

[0045]FIG. 2B illustrates an example of a chain of linked product 20 chthat includes clips 14 applied both singularly and in pairsconcurrently. As shown, the chain of linked product 20 ch includes aforward chub L₁, intermediate chubs L₂-L₄, and a rearward chub L₅. Theforward chub and the rearward chub, L₁, L₅ have two clips 14 wrappedthereabout concurrently to form closed clips 14 c at a forward tail andone closed clip 14 c at a rearward tail (positions marked as “A). Theintermediate links L₂-L₄ have a single clip 14 applied to voided casingmaterial 20 (marked as positions “B”). A loop may be added to theforward or rearward tail to hang the chain on a subsequent processingapparatus as desired (not shown). The sealed product can be cut betweenthe dual applied clips at position A as indicated by the knife position“K” to release the chain 20 ch and start a new chain as desired.

[0046]FIG. 3 is a schematic illustration of certain components that maybe included in a system 111 according to embodiments of the presentinvention. It will be appreciated that in certain embodiments, twoproximately positioned clip attachment mechanisms can be used each withits own clip feed. One clip attachment mechanism can be configured tosubstantially continuously apply a closure clip to the product with eachcycle during production of a chain and the other clip attachmentmechanism can be configured to selectively apply a closure clip to theproduct as described above. As shown in FIG. 3, the system can include acontroller 112 that may be configured to direct the actuation of aretraction actuation cylinder 210 and first and second pusher actuationcylinders 310, 310 ₂. The controller 112 may also be configured tocontrol the operation of a voiding plate(s) actuation mechanism 116 thatcan be used to clear the filler material from the casing 20 (FIG. 1)before the closure clip is attached thereto, as is well known to thoseof skill in the art. The controller 112 can be used to separately and/orjointly actuate (typically in concert) both the first and secondattachment punch mechanisms 118 ₁, 118 ₂ (that may engage punch 16 asshown in FIG. 1, or a different punch or attachment mechanism)associated with the first and second clip attachment mechanisms. Thecontroller 112 may also be configured to direct the actuation of theknife actuation mechanism 114 that is used to separate serial chainsbetween closure clips.

[0047]FIG. 4 is a flow chart of operations that can be used to automatethe closure process according to embodiments of the present invention.Clips are fed on a feed rail to a clip window in communication with aclip attachment mechanism (block 120). It is determined whether a dualclip delivery is desired at this time. If no, it is decided whether asingle clip delivery is desired (block 125). If it is determined that adual clip delivery is desired, the retraction cylinder is held in aretracted state and the clip pusher cylinder can be extended (block123). It is then determined whether a single clip delivery is desired(block 125); if not, it can be queried again whether another dual clipis desired (block 121) or whether to ask for operator input (block 126).If single clip delivery is desired, the pusher cylinder is retracted andthe retraction cylinder is actuated to retract the clips away from theclip window (block 127). Sensors can obtain data that can beinterrogated to determine whether the desired number of links and/ordesired length of chain has been produced (block 129). It can bedetermined whether the link is the last in the chain. If so, a new chaincan be started after applying two clips (block 123). If no, theretraction cylinder can be maintained in its engaged position with theclips held away from the clip window (block 127).

[0048]FIG. 5 illustrates one embodiment of a retraction assembly 200with a retraction assembly actuation cylinder 210. Also shown is a clipadvancement mechanism 300 with its respective actuation cylinder 310. Asshown, the retraction assembly 200 includes a retraction jaw 225 withlegs 226, 227 that are pivotably attached to a mounting bracket 225 m ata corresponding first end portion thereof 226 p, 227 p. The mountingbracket 225 is operatively associated with the cylinder 210 and moves upand down as the cylinder 210 is actuated, as will be discussed furtherbelow.

[0049] Still referring to FIG. 5, the retraction jaw 225 can include anextension spring 228 that extends between the legs 226, 227. Each leg226, 227 may include an aperture 226 a, 227 a with a pin 229 extendingacross that can hold opposing ends of the spring 228 to bias the legs226, 227 to move toward each other in operation. In certain embodiments,the spring 228 can be a coil spring, which can apply a desired biasingspring force to help bring the legs 226, 227 together. An example of asuitable spring is a spring made from 0.026 stainless steel wire with a.standard 1″ length. The spring ratings can be about 2.43 pounds per inch(typically about +/−10%) with a deflection at load of about 0.94 and aload of about 2.66 in-lb. The spring length at mechanism rest is about1.727 inches and the spring length at mechanism engaged is about 1.233.Typically, there is little force (such as less than about 1.5 in-lb)applied to the retraction legs 226, 227 and/or fingers 226 f, 227 f tobring them together.

[0050] The retraction jaw 225 can also include two jaw stop pins 230 ₁,230 ₂ that reside inside of and below the first end portions of the legs226, 227. The jaw stop pins 230 ₁, 230 ₂ may be alternately configuredas a single pin or track that can extend across the jaw retractionbracket or frame 225 a sufficient distance to engage both legs 226, 227.The second end portions 226 c, 227 c are configured to engage the clips14 to move the clips 14 away from the clip window 24 and/or the clipclosure path 12 (FIG. 1). As shown in FIG. 5, the second end portions226 c, 227 c are lower portions of the legs 226, 227 which includeoutwardly extending fingers 226 f, 227 f that can be configured tostraddle a portion of the outer perimeter of the clip 14 (FIG. 9A). Asshown, the fingers 226 f, 227 f can extend across a major portion of thelength of the clip legs 14L (FIG. 9C) leaving the crown 14C (FIG. 9C)area substantially open. However, other gripping or contactingconfigurations may also be used as long as sufficient force is appliedto the clips 14 to be able to selectively and controllably retract themaway from the clip window 24 (FIG. 1) and, in certain embodiments, so asto be able to hold the clips 14 in a retracted position for a desiredinterval.

[0051]FIG. 6 illustrates the retraction assembly 200 and the clipadvancement assembly 300 with the retraction assembly 200 and retractionjaw 225 in a rest position and with the cylinder 210 placing the rod 210r in an extended position. FIG. 7 also illustrates the retractionassembly 200 and retraction jaw 225 in the rest position with rod 210 ractuated to the extended position and the legs 226, 227 of the jaw 225spread apart and disengaged from the clips 14. During normal operation(in which single clip applications are not used), the system may beoperated so as to leave the jaw retraction cylinder 210 with the jawlegs open, which allows the clip pusher cylinder 310 to cycle duringeach machine cycle (as shown in FIG. 8A).

[0052] As shown in FIG. 9A, the fingers 226 f, 227 f extend outwardly adistance sufficient to straddle opposing sides of the clip or clips 14(shown as contacting two abutting clips 14) and the inner surface of thefingers 226 f, 227 f can be formed with a tooth profile that, uponcontact, can mate with the profile of abutting clips 14. Other grippingconfigurations can also be used. For example, the fingers 226 f, 227 fmay include surfaces with materials which can frictionally engage theclips 14, such as elastomeric or rubber coatings. In addition, theretraction jaw may be configured to engage only one side of the clips orother portions of the clips.

[0053]FIG. 8A illustrates the clip advancement assembly 300 with theassociated pusher actuation cylinder 310 in operation and with the rod310 r in an extended state. A pusher pawl 325 is pivotably mounted tothe bracket 325 m at pivot 325 p. The pusher pawl 325 may also be springloaded with a torsion spring (not shown) to help provide sufficientdownward force onto the clips 14. The pusher pawl 325 includes a forwardedge 325 e portion that engages a clip or clips on the rail 22. Theforward edge portion 325 e may be configured as a protruding tooth whichcan enter (from a side) the space between abutting clip legs as shown inFIG. 8A. The rod 310 r is connected to a mounting bracket 325 m and canmove the mounting bracket 325 m, and in turn, pusher 325, in a desiredreciprocating motion. The pusher pawl 325 may also include a manualdisengagement lever 326.

[0054] As also shown in FIG. 8A, the clip advancement assembly 300 caninclude a stop anvil 328 that can be positioned above the pusher pawl325. The stop anvil 328 can have a downwardly extending portion 328 dthat, in operation, forces the pusher pawl 325 to pivot down anddisengage the clips 14 as shown in FIG. 8B when the cylinder 310 has therod 310 r in a retracted state. FIG. 8B show both the clip advancementassembly 300 with the associated cylinder 310 and the clip retractionassembly 200 with the associated cylinder 210 in a rest state (i.e.,neither engaged with clips).

[0055]FIG. 9A illustrates the retraction assembly 200 with theretraction cylinder 210 actuated to place rod 210 r in a retracted stateand with the jaw 225 engaging the clips 14 to direct the clips 14 toretract (as indicated by the arrow located adjacent the clip rail 22).FIG. 9B illustrates the configuration of the advancement assembly 300when the retraction assembly 200 operatively engages the clips 14. Asshown, the pusher pawl 325 is pivoted down so that it does not engagethe clips 14 while the clip jaws 225 are engaged to retract the clips14. FIG. 9C illustrates the configuration of the jaw 225 with respect tothe clip when not engaging the clips 14. As shown, in this embodiment,the clips 14 include a crown 14 c and two opposing legs 14L. However, asnoted above, the present invention can be used with other clipconfigurations.

[0056] Referring again to FIG. 7, as the retraction cylinder 210 isextended (moving toward a rest state), legs 226, 227 move down and theupper portions thereof 226 u, 227 u approach the stop pins 230 ₁, 230 ₂.The inner surfaces of the legs 226 i, 227 i act as cam followers, withthe jaw stop pins 230 ₁, 230 ₂ acting as the cam. Thus, as the legs 226,227 move down responsive to the rod 210 r moving into the extendedstate, the legs 226, 227 are forced apart. The jaw stop pins 230 ₁, 230₂ can be statically mounted to remain in a fixed position on theretractor assembly 200 (and/or pusher assembly 300).

[0057] As shown herein, the cylinders 210 and 310 move respectivebrackets 225 m, 325 m along a generally vertical actuation axis.However, other actuation orientations may also be used with other clipattachment and/or clip feed configurations. In addition, as shown, theclip advancement assembly 300 is located above the clip retractionassembly 200 so that the advancement assembly 300 pushes the clips 14 inthe feed direction and the retraction assembly 200 pulls the clips awayfrom the clip window in the reverse direction. However, the twoassemblies 200, 300 can be positioned in the reverse or even at the samevertical position.

[0058] The cylinders 210, 310 can be double-acting. As is well known tothose of skill in the art, fluid (typically pneumatic) pressure isprovided against the surface of the piston to provide a substantiallyconstant and controlled driving force for the respective assembly 200,300. When the piston reaches the lower end (or upper end) of its runwithin the cylinder, the fluid driving forces can be reversed so thatthe piston can return to its initial driving position at the top orbottom of the cylinder.

[0059] Now describing a typical sequence of operations, with referencefirst to FIG. 8A, clips are fed onto the clip rail 22. The clip pushercylinder 310 extends the rod 310 r to engage the clip pusher pawl 325with the clips 14 and push the clips 14 in the feed direction. FIG. 7illustrates the retraction assembly 200 during this operation. Then,after a dual clip application, or when a single clip application isdesired, as shown in FIG. 8B, the clip pusher cylinder 310 retracts therod 310 r until the clip pusher pawl 325 is against the stop anvil 328and the pawl 325 disengages the clips 14. FIG. 7 shows that, startingwith the cylinder 210 holding the rod 210 r in an extended state, air isapplied to the rod side of the cylinder 210 causing the cylinder rod 210r to retract. As the cylinder 210 and rod 210 r retract, the legs 226,227 of the retraction jaw 225 start to close and complete their travelto a closed position to engage the clips 14 as shown in FIG. 9A. Theretraction jaw legs 226, 227 are drawn together by the extension spring228. The timing of the jaw closure can allow the teeth 226 t, 227 t toengage the clip legs 14L (FIG. 9C) prior to the retraction cylinder 210reaching full stroke. Once the retraction jaw teeth 226 t, 227 t firmlyengage the clips 14, the remaining stroke of the cylinder 210 allows therod 210 r to pull the clips 14 away from the clip window and associatedattachment mechanism. By preventing a clip from being fed into theattachment device, no clip is applied via the first clip mechanismthereby allowing a single clip to be applied to the product. Thisoperational configuration can remain until the end of the chain ofchubs, at which time a double set of clips may be desired as notedabove. A knife cut can be made intermediate the dual applied clips tostart a new chain and/or release the first chain (shown at position “k”in FIG. 2B). The length and number of chubs can vary as noted above.During the time period from the last single clip application and the endof the chub chain, where a double clip and knife cut is applied, theretraction jaw 225 can return to its rest configuration with the stopjaw pins 230 ₁, 230 ₂ forcing the legs to open as shown in FIG. 7 anddescribed further above.

[0060] The operation and sequence of events can be controlled by aprogrammable logic controller. The number of pieces in the chain and/orlength of the chain can be selected by an operator input using a HumanMachine Interface to communicate with the controller as is well known tothose of skill in the art.

[0061]FIG. 10 is a block diagram of exemplary embodiments of dataprocessing systems that illustrates systems, methods, and computerprogram products in accordance with embodiments of the presentinvention. The processor 410 communicates with the memory 414 via anaddress/data bus 448. The processor 410 can be any commerciallyavailable or custom microprocessor. The memory 414 is representative ofthe overall hierarchy of memory devices containing the software and dataused to implement the functionality of the data processing system 405.The memory 414 can include, but is not limited to, the following typesof devices: cache, ROM, PROM, EPROM, EEPROM, flash memory, SRAM, andDRAM.

[0062] As shown in FIG. 10, the memory 414 may include severalcategories of software and data used in the data processing system 405:the operating system 452; the application programs 454; the input/output(I/O) device drivers 458; the clip push/pull control module 450; and thedata 456.

[0063] The data 456 may include a look-up chart of different products,filling rates, selectable chain lengths and link lengths and the like451 corresponding to particular or target products for one or moreproducers, which may be displayed to allow an operator to select desiredoperational parameters at the start of each shift and/or production runand the like.

[0064] As will be appreciated by those of skill in the art, theoperating system 452 may be any operating system suitable for use with adata processing system, such as OS/2, AIX, DOS, OS/390 or System390 fromInternational Business Machines Corporation, Armonk, N.Y., Windows CE,Windows NT, Windows95, Windows98 or Windows2000 from MicrosoftCorporation, Redmond, Wash., Unix or Linux or FreeBSD, Palm OS fromPalm, Inc., Mac OS from Apple Computer, LabView, or proprietaryoperating systems. The I/O device drivers 458 typically include softwareroutines accessed through the operating system 452 by the applicationprograms 454 to communicate with devices such as I/O data port(s), datastorage 456 and certain memory 414 components and/or the dispensingsystem 420. The application programs 454 are illustrative of theprograms that implement the various features of the data processingsystem 405 and preferably include at least one application whichsupports operations according to embodiments of the present invention.Finally, the data 456 represents the static and dynamic data used by theapplication programs 454, the operating system 452, the I/O devicedrivers 458, and other software programs that may reside in the memory414.

[0065] While the present invention is illustrated, for example, withreference to the clip push/pull module 450 being an application programin FIG. 10, as will be appreciated by those of skill in the art, otherconfigurations may also be utilized while still benefiting from theteachings of the present invention. For example, the module 450 may alsobe incorporated into the operating system 452, the I/O device drivers458 or other such logical division of the data processing system 405.Thus, the present invention should not be construed as limited to theconfiguration of FIG. 10, which is intended to encompass anyconfiguration capable of carrying out the operations described herein.

[0066] The I/O data port can be used to transfer information between thedata processing system 405 and the closure attachment mechanism (such asfor chubbed linked product) 420 or another computer system or a network(e.g., the Internet) or to other devices controlled by the processor.These components may be conventional components such as those used inmany conventional data processing systems which may be configured inaccordance with the present invention to operate as described herein.

[0067] While the present invention is illustrated, for example, withreference to particular divisions of programs, functions and memories,the present invention should not be construed as limited to such logicaldivisions. Thus, the present invention should not be construed aslimited to the configuration of FIG. 10 but is intended to encompass anyconfiguration capable of carrying out the operations described herein.

[0068] The flowcharts and block diagrams of certain of the figuresherein illustrate the architecture, functionality, and operation ofpossible implementations of selective implementation of single and dualclip closure means according to the present invention. In this regard,each block in the flow charts or block diagrams represents a module,segment, or portion of code, which comprises one or more executableinstructions for implementing the specified logical function(s). Itshould also be noted that in some alternative implementations, thefunctions noted in the blocks may occur out of the order noted in thefigures. For example, two blocks shown in succession may in fact beexecuted substantially concurrently or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved.

[0069] The foregoing is illustrative of the present invention and is notto be construed as limiting thereof. Although a few exemplaryembodiments of this invention have been described, those skilled in theart will readily appreciate that many modifications are possible in theexemplary embodiments without materially departing from the novelteachings and advantages of this invention. Accordingly, all suchmodifications are intended to be included within the scope of thisinvention as defined in the claims. In the claims, means-plus-functionclauses, where used, are intended to cover the structures describedherein as performing the recited function and not only structuralequivalents but also equivalent structures. Therefore, it is to beunderstood that the foregoing is illustrative of the present inventionand is not to be construed as limited to the specific embodimentsdisclosed, and that modifications to the disclosed embodiments, as wellas other embodiments, are intended to be included within the scope ofthe appended claims. The invention is defined by the following claims,with equivalents of the claims to be included therein.

That which is claimed is:
 1. A method for supplying a clip to a clipwindow associated with a closure attachment mechanism adapted to allow asingle clip or two clips to be controllably applied to a target tubularwork piece in a closure zone in an automated manner, comprising:automatically forcing a plurality of clips to travel in a firstpredetermined clip travel path having a forward direction toward a firstpunch path in a closure zone at a first point in time; automaticallyselectively retracting the plurality of clips so that the clips travelin a reverse direction along the first predetermined clip travel pathaway from the first punch path; and then automatically forcing theplurality of clips to again travel in the forward direction along thefirst predetermined clip travel path at a second point in time.
 2. Amethod according to claim 1, further comprising: automatically holdingthe plurality of clips above a first clip window associated with thefirst punch path in the closure zone for a desired interval after saidretracting step and before said second forcing step, the intervalassociated with the number of target tubular workpieces that passthrough the closure zone without receiving a clip from the first punchpath; and automatically intermittently attaching a clip to selectedtubular workpieces that pass through the closure zone using clipsadvanced along the first clip path to the first punch path during thefirst and second forcing steps.
 3. A method according to claim 2,further comprising: repeatedly forcing a second plurality of clips totravel in a second predetermined clip travel path having a forwarddirection toward a second punch path with a second clip window;automatically concurrently attaching one clip from the first clip punchpath and one clip from the second clip punch path thereby selectivelyapplying one clip to a greater number of target tubular workpieces andtwo clips to fewer numbers of target tubular workpieces as the tubularworkpieces move through the closure zone.
 4. A method according to claim1, wherein the tubular workpieces are stuffed food product held in acasing material, said method further comprising advancing the tubularstuffed food product in a predetermined forward travel path and stallingthe forward movement during the forcing steps.
 5. A method according toclaim 4, wherein the stuffed food products are meat products.
 6. Amethod according to claim 1, further comprising reciprocating a firstpunch to travel along the first punch path during the first and secondforcing steps and the retracting step to selectively direct a clippositioned in the clip window to wrap about an end portion of onetubular product in the first clip window during the first and secondforcing steps.
 7. A method according to claim 1, wherein the firstforcing step comprises pushing the clips to travel in a generallydownward direction, and wherein the retracting step comprises pullingthe clips to travel in a generally upward direction.
 8. A methodaccording to claim 1, further comprising feeding a spool of attachedclips to travel along a generally downwardly extending static rail witha lateral portion that defines the first predetermined travel path sothat the forwardmost portion of the spool of clips enters a clip windowto engage with a punch attachment mechanism in the first punch path. 9.A method according to claim 8, further comprising punching a clip in theclip window to force the clip to wrap around an underlying targetworkpiece.
 10. A method according to claim 9, wherein the clips aremetallic with a discontinuous perimeter having generally open endportions that when attached to the tubular work product sealably enclosespaced apart end portions of the tubular work product.
 11. A methodaccording to claim 1, wherein the second forcing step comprisescontacting an outer perimeter portion of at least one clip with aretraction member having a jaw with first and second opposing spacedapart hinged jaw members in communication with an extension springconfigured to allow the hinged jaw members to open and close a desireddistance to pull the clips in a generally upward direction away from aclip feed direction.
 12. A method according to claim 11, wherein thefirst forcing step comprises contacting the outer perimeter of at leastone of the plurality of clips with a pivotable pusher pawl and applyingforce in a generally forward direction to push the plurality of clips inthe clip feed direction.
 13. A method according to claim 12, whereinsaid retracting step comprises: disengaging the pusher pawl from theclips; and engaging the jaw members of the retraction member with aplurality of adjacent clips.
 14. A method according to claim 13, whereinthe clip has a central crown region that terminates into two opposingleg portions, and wherein the jaw members have a contact edge portionwith a profile that corresponds to the outer profile of the legs ofabutting clips.
 15. A method according to claim 13, wherein said firstand second forcing steps comprise: disengaging the jaw members of theretraction member from the clips; and engaging the pusher pawl with theclips.
 16. A method according to claim 12, wherein the pusher pawl isdisposed above the retraction member.
 17. A method according to claim16, further comprising separating the retraction jaws a suitabledistance to release the clips after the retracting step and before thesecond forcing step.
 18. A method according to claim 17, wherein theopposing jaw members have legs with opposing top and bottom endportions, the top end portions being pivotably connected to theretraction mechanism and the bottom end portions defining the clipcontact portion with the extension spring laterally extendingtherebetween.
 19. A method according to claim 18, wherein the retractionmember further comprises at least one jaw stop disposed above theretraction jaw members, the retraction jaw members each having an innersurface that faces the other, wherein, in operation, the jaw stopdefines a cam surface and the jaw retraction member inner surfacescooperate with the jaw stop cam surface to force the spaced apart legsto open and stretch the spring extending therebetween.
 20. A methodaccording to claim 15, wherein the pusher pawl is disposed above theretraction member, said method further comprising rotating the pusherpawl upon contact with a stop anvil disposed above the pusher pawl tospace the head away from the clips to thereby disengage the pusher pawlfrom the clips.
 21. A method for controllably supplying a clip to a clipwindow associated with a closure attachment mechanism having a closuredelivery path for allowing attachment of a single clip or two clipsconcurrently to a target tubular work piece in a closure zone,comprising: automatically pushing a plurality of clips to travel in afirst predetermined clip travel path having a forward direction toward afirst closure delivery path in a closure zone at a first point in time;automatically selectively pulling the plurality of clips so that theclips travel in a reverse direction along the first predetermined cliptravel path; and then automatically pushing the plurality of clips toagain travel in the forward direction along the first predetermined cliptravel path at a second point in time.
 22. An apparatus for supplying aclip to a clip window associated with a closure attachment mechanismhaving a closure delivery path for attaching a single clip or two clipsto a target tubular work piece in a closure zone, comprising: means forforcing a plurality of clips to travel in a first predetermined cliptravel path having a forward direction toward a first closure deliverypath in a closure zone at a first point in time; means for selectivelyretracting the plurality of clips so that the clips travel in a reversedirection along the first predetermined clip travel path; and then meansfor forcing the plurality of clips to again travel in the forwarddirection along the first predetermined clip travel path at a secondpoint in time.
 23. An apparatus according to claim 22, furthercomprising means for holding the plurality of clips above a first clipwindow associated with the first closure delivery path in the closurezone for a desired interval, the interval associated with the number oftarget tubular workpieces that pass through the closure zone withoutreceiving a clip from the first closure delivery path.
 24. An apparatusaccording to claim 23, further comprising means for repeatedly forcing asecond plurality of clips to travel in a second predetermined travelpath having a forward direction toward a second closure delivery pathwith a second clip window at the first and second points in time andwhile the means for retracting and holding are applied to the firstplurality of clips; means for concurrently attaching one clip from thefirst clip closure delivery path and one clip from the second clipclosure delivery path during the first and second points in time; andmeans for selectively applying one clip to a greater number of targettubular workpieces and two clips to fewer numbers of target tubularworkpieces as the tubular workpieces move through the closure zone. 25.An apparatus according to claim 22, wherein the tubular workpieces arestuffed food product held in a casing material, said apparatus furthercomprising means for advancing the tubular stuffed food product in apredetermined forward travel path and stalling the forward movementwhile the clips are applied by the means for forcing.
 26. An apparatusaccording to claim 25, wherein the stuffed food products are meatproducts or cheese products.
 27. An apparatus according to claim 22,wherein the means for retracting comprises means for pulling the clipsin a generally upward direction by contacting an outer perimeter portionof at least one clip with a retraction member having a jaw with firstand second opposing spaced apart hinged jaw members in communicationwith an extension spring configured to allow the hinged jaw members toopen and close a desired distance.
 28. An apparatus according to claim27, wherein the means for forcing comprises pushing the plurality ofclips in the forward direction by contacting the outer perimeter of atleast one of the plurality of clips with a pivotable pusher pawl andapplying force in the generally forward direction.
 29. A system forattaching closure clips to elongate or tubular products held in casingmaterials, comprising: a curvilinear clip rail having opposing top andbottom end portions and defining a generally downwardly extending clipfeed direction; a clip entry window in communication with the bottom endportion of the clip rail and a clip closure delivery path incommunication with an attachment mechanism that is adapted to wrap aclip about a target tubular work piece; a clip pusher configured toselectively engage with clips held on the clip rail to force the clipsin the feed direction; and a clip retraction assembly configured toselectively engage with clips held on the clip rail to force the clipsaway from the clip window and away from the clip feed direction.
 30. Asystem according to claim 29, further comprising: a first actuationcylinder in communication with the clip pusher; a second actuationcylinder in communication with the clip retraction member; and a controlmodule configured to direct the actuation of the first and secondcylinders to selectively feed or not feed a clip through the clipwindow.
 31. A system according to claim 30, further comprising a framemember configured to cooperate with the first actuation member and tohold the clip pusher, and a pusher stop member disposed above the clippusher, wherein the clip pusher is pivotably mounted to the frame memberand, wherein, in operation, when the first actuation cylinder travels toan extended state, the clip pusher engages at least one clip to forcethe clips in the feed direction and when the first actuation cylinder isin a retracted state, the pusher stop member pivots the clip pusher awayfrom the clip rail to disengage from the clips.
 32. A system accordingto claim 30, further comprising a mounting member that holds theretraction assembly and is in communication with the second actuationcylinder, the retraction assembly having a retraction jaw withcooperating spaced apart first and second legs, each leg having opposingtop and bottom portions, the leg top portions being pivotably attachedto the mounting member, the retraction jaw further comprising anextension spring extending between the first and legs, wherein, inoperation, when the second actuation cylinder is in an extended state,the retraction assembly is configured with the jaw legs spaced apartsufficiently to not contact the clips on the clip rail, and when thesecond actuation cylinder travels to a retracted state, the legs of theretraction assembly jaw close a distance to engage opposing sides of atleast one clip and move the clips on the clip rail upward so that theclip window is devoid of a clip therein.
 33. A system according to claim29, wherein the attachment mechanism comprises a punch, which, inoperation, operates substantially continuously during production of achain of a plurality of linked, encased tubular product.
 34. A computerprogram product for operating a shirred casing voiding/clippingapparatus having two proximate clip attachment mechanisms with first andsecond clip travel paths to selectively deliver one clip or two clipsconcurrently to a chain of chub product, the computer program productcomprising: a computer readable storage medium having computer readableprogram code embodied in said medium, said computer-readable programcode comprising: computer readable program code that controllablyactuates a first actuation cylinder to push clips in a first clip feeddirection; and computer readable program code that controllably actuatesa second actuation cylinder to pull clips away from the clip feeddirection.
 35. A computer program product according to claim 34, furthercomprising computer readable program code that allows a user to select adesired number of links of chubs and/or a desired chain length of linkedchubs.
 36. A computer program product according to claim 35, furthercomprising computer readable program code that directs the first andsecond actuation cylinders to apply the appropriate number of single anddual clips at the appropriate links in the chain based on the userinput.